Alternating tooth chain ring

ABSTRACT

The present disclosure relates to a chain ring having teeth positioned in one of three lateral positions. At least one tooth may be placed in each lateral position. At least half the teeth may be positioned in a middle lateral position. The teeth in the first and third lateral positions may apply opposing lateral forces to a bicycle drive chain.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/945,408 filed Feb. 27, 2014 and U.S. Provisional Application No.62/039,100 filed Aug. 19, 2014.

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

(Not Applicable)

REFERENCE TO AN APPENDIX

(Not Applicable)

BACKGROUND OF THE INVENTION

The present disclosure relates generally to a chain ring for a vehicle.More particularly, the present disclosure relates to a chain ring thathas alternating teeth that may form a wave pattern.

Drive chains used for vehicles, like bicycles, are formed of alternatinglinks. A first link has a narrow opening. The flanking second links arewider. As may be seen best in FIG. 1, bicycle drive chains may be madefrom outer links 100 and inner links 102. In general, the length 104 ofeach link is about the same. However, the outer links 100 and the innerlinks 102 differ in width. The outer link 100 may have a width 106 widerthan the width 103 of the inner link 102. It will be understood by aperson having ordinary skill in the art that in a conventional bicycledrive chain, the series of alternating outer links 100 and inner links102 alternate for whatever length of drive chain is deemed desirable.The chain as a whole may be referred to as the chain 150.

A conventional chain ring is shown in FIG. 2. The chain ring 210includes a plurality of teeth 212 of substantially similar size andshape. The use of teeth of substantially similar size and shape mayallow for gaps between an outer surface 214 of a tooth 212 and a firstinner lateral surface 110 or a second inner lateral surface 112 of anouter link 100 of a drive chain (see FIG. 1). In many conventionalapplications, these gaps may not drastically hinder performance, but mayincrease the risk of chain disengagement.

In the past, some manufacturers have attempted to create chains thathave alternating teeth. These alternating teeth may be configured tocorrespond in size and shape more closely to the alternating width ofthe links in a chain. However, the use of teeth of larger size also mayincrease the weight of the chain ring and the vehicle, which may bedeemed undesirable. In addition, the use of a tooth of larger size may,in some cases, increase the risk of a tooth catching on a portion of thechain due to that increased size, thereby creating damage or risk ofinjury. Further, the use of such a design may increase the likelihood ofdirt, mud, or other debris becoming entangled in the ring and/or betweenthe teeth of the ring and impeding the meshing of the teeth and thechain.

BRIEF SUMMARY OF THE INVENTION

In one embodiment, a chain ring may include a body and a plurality ofteeth defining a single ring of teeth that are circumferentially affixedto the body. The body may have a thickness. At least a first one of theplurality of teeth may be positioned at a first position across thethickness. At least a second one of the plurality of teeth may bepositioned at a second position across the thickness. At least a thirdone of the plurality of teeth may be positioned at a third positionacross the thickness. The first, second, and third positions may differfrom one another.

The at least a first one and the at least a third one may be mirrorimages of one another. Each of the plurality of teeth may have asubstantially rectangular end face. The at least a first one and the atleast a third one may each have a substantially hat-shaped cross sectionat their respective bases. The at least a first one and the at least asecond one may be placed adjacent one another and the at least a secondone and the at least a third one may be placed adjacent one another. Thechain ring may further include at least a fourth one of the plurality ofteeth. The at least a fourth one may be positioned at the secondposition across the thickness. The chain ring may further comprise atleast one tooth in a fourth position across the thickness. The chainring may further comprise at least one tooth in a fifth position acrossthe thickness. Each tooth in each position across the thickness may becircumferentially spaced from each other tooth.

In another embodiment, a chain ring may include a plurality of teeth.Each tooth may have an end face having a centerpoint. Centerpoints of atleast five adjacent teeth may form a substantially undulating pattern.At least one centerpoint of at least one of the at least five teeth maybe positioned away from a peak or valley of the substantially undulatingpattern.

Three of the at least five teeth may be positioned away from a peak orvalley of the substantially undulating pattern. The substantiallyundulating pattern may be substantially regular around a circumferenceof the chain ring. The substantially undulating pattern may besubstantially a triangle wave.

In another embodiment, a chain ring includes a plurality of teeth. Eachtooth may be positioned in one of a first, second, and third lateralposition. At least one tooth may be positioned in the first lateralposition. At least one tooth may be positioned in the third lateralposition. At least half the teeth may be positioned in the secondlateral position.

Exactly half the teeth may be positioned in the second lateral position.The second lateral position may be laterally between the first lateralposition and the third lateral position. About a quarter of the teethmay be positioned in the first lateral position and about a quarter ofthe teeth may be positioned in the third lateral position. The teeth maybe positioned in a substantially repeating pattern of lateral positionsalong a circumference of the chain ring. The teeth may be positioned ina substantially repeating pattern of four teeth. The repeating patternmay be a tooth in the second lateral position, a tooth in the firstlateral position, a tooth in the second lateral position, and a tooth inthe third lateral position.

In another embodiment, a chain ring may include a plurality of teeth.Each tooth may be positioned at a respective lateral position on athickness of the chain ring. At least a first tooth and a second toothof the plurality of teeth may be circumferentially spaced from oneanother and positioned at a first lateral position. At least three ofthe plurality of teeth may be circumferentially positioned between thefirst tooth and the second tooth. Each of the at least three teeth maybe positioned at a lateral position different from the first lateralposition.

At least two of the at least three teeth may be positioned at a secondlateral position. At least one of the at least three teeth may bepositioned at a third lateral position. The tooth positioned at thethird lateral position may be circumferentially positioned between theat least two teeth positioned at the second lateral position. The atleast three teeth may each be positioned at a second lateral position.No tooth in the first lateral position may be positioned between thefirst tooth and the second tooth.

In another embodiment, the chain ring may include a body and a pluralityof teeth affixed around a circumference of the body. The teeth may beconfigured to engage a chain without shifting. Some of the plurality ofteeth may be configured to engage a first lateral side of a first linkof the chain, thereby applying a force to the chain in a first lateraldirection. Some of the plurality of teeth may be configured to engage asecond lateral side of a second link of the chain, thereby applying aforce to the chain in a second lateral direction. Some of the pluralityof teeth may be configured to apply no substantial lateral force to thechain.

When a lateral force is applied to the chain, the chain may be permittedto flex in that direction. The first lateral force and the secondlateral force may be approximately equal. The teeth may be positioned inthree lateral positions. The teeth in the first lateral position may beconfigured to impart a first lateral force. The teeth in the thirdlateral position may be configured to impart a second lateral force. Theteeth in the second lateral position may be configured to impartsubstantially no lateral force. At least one tooth may be configured toengage a first lateral side of an outer link of the chain. At least onetooth may be configured to engage a first lateral side of an inner linkof the chain.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a top and side view of a conventional chain;

FIG. 2 is a side view of a conventional chain ring;

FIG. 3 is a perspective view of an embodiment of a chain ring inaccordance with the disclosure;

FIG. 4 is an enlarged view of a portion of the chain ring as shown by adashed circle in FIG. 3;

FIG. 5 is a close view, represented by the dashed circle of FIG. 6, ofone end of a chain ring in accordance with the embodiment of FIG. 3;

FIG. 6 is an end view of the chain ring, being from further away thanthe view of FIG. 5;

FIG. 7 is side view of the chain ring in accordance with the embodimentof FIG. 3;

FIG. 8 is an enlarged view of a portion of the chain ring as shown inthe dashed circle of FIG. 7;

FIG. 9 is a cross-sectional view of a tooth taken along line 9-9 of FIG.4;

FIG. 10 is a cross-sectional view of another tooth taken along line10-10 of FIG. 4;

FIG. 11 is a schematic view showing one alternative embodiment of thechain ring in accordance with the disclosure;

FIG. 12 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 13 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 14 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 15 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 16 is a side view of a bicycle showing one embodiment of a chainring in operative position;

FIG. 17 is a sectional view of the embodiment of FIG. 16 taken alongline 17-17 and illustrating a tooth configuration similar to that ofFIG. 11;

FIG. 18 is a side view of another alternative embodiment of a chain ringin accordance with the disclosure;

FIG. 19 is a sectional view of the embodiment of FIG. 18 taken alongline 19-19;

FIG. 20 is a sectional view of the embodiment of FIG. 18 taken alongline 20-20;

FIG. 21 is a sectional view of the embodiment of FIG. 18 taken alongline 21-21;

FIG. 22 is a closer view of an arc of the embodiment of FIG. 18;

FIG. 23 is a side view of yet another alternative embodiment of a chainring in accordance with the disclosure;

FIG. 24 is a sectional view of the embodiment of FIG. 23 taken alongline 24-24;

FIG. 25 is a sectional view of the embodiment of FIG. 23 taken alongline 25-25;

FIG. 26 is a sectional view of the embodiment of FIG. 23 taken alongline 26-26;

FIG. 27 is a closer view of an arc of the embodiment of FIG. 23;

FIG. 28 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 29 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure;

FIG. 30 is a sectional view of the embodiment of FIG. 16 taken alongline 17-17 and illustrating a tooth configuration similar to that ofFIG. 28;

FIG. 31 is a sectional view of the embodiment of FIG. 16 taken alongline 17-17 and illustrating a tooth configuration similar to that ofFIG. 29;

FIG. 32 is a schematic view showing another alternative embodiment ofthe chain ring in accordance with the disclosure; and

FIG. 33 is a side view of a tooth showing a profile that may be used inany of the embodiments shown.

In describing the preferred embodiment of the invention which isillustrated in the drawings, specific terminology will be resorted tofor the sake of clarity. However, it is not intended that the inventionbe limited to the specific term so selected and it is to be understoodthat each specific term includes all technical equivalents which operatein a similar manner to accomplish a similar purpose. For example, theword connected or terms similar thereto are often used. They are notlimited to direct connection, but include connection through otherelements where such connection is recognized as being equivalent bythose skilled in the art.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure incorporates by reference the disclosures of U.S.Provisional Patent Application Ser. No. 61/945,408, filed Feb. 27, 2014and U.S. Provisional Application No. 62/039,100 filed Aug. 19, 2014.

In this detailed description, various terms relating to direction may beused. The elements discussed herein relate to a bicycle. Because, in itsoperable position, a bicycle is oriented generally vertically, i.e.,perpendicular to the ground, the direction terms refer to the positionof an element relative to gravity when the bicycle is in its operableposition. Accordingly, for example, the term “downwardly” refers to thedirection towards the ground when the bicycle is in its operableposition, and the term “forwardly” relates to a direction towards afront wheel of the bicycle when it is in its operable position. Further,the terms “inboard” and “outboard” may be used. The term “inboard”describes a position between one item and a vertical plane substantiallybisecting the bicycle. The term “outboard” describes a position of anobject further from the vertical centerplane of the bicycle. Inaddition, the terms “bicycle” and “bike” are used hereininterchangeably. A person having ordinary skill in the art willunderstand that if something is referred to as one, it can refer to theother.

The overall shape and configuration of one embodiment of the chain ringaccording to the present disclosure is shown in FIGS. 3-8. Turning firstto FIG. 7, the chain ring 700 may include a body 702 and a plurality ofteeth 704 circumferentially affixed or affixed around a circumference706 of the body 702. It is noted that in the embodiment shown in FIGS.3-8, along with other embodiments illustrated and described, the chainring 700 is shown as having a “direct mount” style. A person havingordinary skill in the art understands that instead of a direct mount, atraditional mount style similar to that shown as being conventional inFIG. 2 could alternatively be used. Other mounting styles may also beappropriate, depending on the wishes of the designers and users. How thechain ring 700 is to be mounted to the vehicle is not of primaryimportance in this disclosure.

The teeth 704 in the disclosed embodiments may be discussed in thedisclosure as being positioned circumferentially with respect to oneanother. In particular, some teeth may be described as beingcircumferentially adjacent one another or circumferentially spaced fromone another. As one example, a first tooth 708 may be circumferentiallyspaced from a second tooth 710. In the embodiment disclosed in FIG. 7,the first tooth 708 and the second tooth 710 may be described as havingthree teeth, specifically the third tooth 712, the fourth tooth 714, andthe fifth tooth 716, circumferentially between the first tooth 708 andthe second tooth 710. Similarly, the third tooth 712 may be described asbeing circumferentially adjacent the first tooth 708 and the fourthtooth 714. When discussing any tooth 704 circumferentially with respectto any other tooth 704, the lateral position, i.e., the position of thetooth 704 along or across a width of the chain ring body 702 is notimportant. Teeth that are circumferentially adjacent one another mayalso be considered positioned serially with respect to one another.

It is noted that in each of the illustrated embodiments, each tooth 704is circumferentially spaced from each other tooth 704. In theseembodiments, no two teeth 704 occupy the same or a similarcircumferential position. In many embodiments, such a design choice maybe made for ease and cost of manufacturing. However, other designchoices regarding co-location or other partial or complete overlappingcircumferentially of multiple teeth could be made if deemed desirable ornecessary by a designer.

The lateral position of the teeth across a width or thickness of thechain ring may be best seen in the perspective views of FIGS. 3 and 4and the side views of FIGS. 5 and 6. As may be seen most clearly in FIG.6, the chain ring 700 may have a thickness 600. Each tooth 704 may bepositioned at a designated or respective lateral position across thethickness 600. As may be seen in FIG. 5, a first tooth 500 may bepositioned at a first lateral position 501. Each of a second tooth 502and a third tooth 504 may be positioned at a second lateral position503. Each of a fourth tooth 506 and a fifth tooth 508 may be positionedat a third lateral position 505. The first position 501, the secondposition 503 and the third position 505 may differ from one another. Thesecond position 503 may be between the first position 501 and the thirdposition 505 and may be considered a middle position. Additional detailsregarding the lateral positions of the teeth will be disclosed below.

In some embodiments, the chain ring 700 may be machined from a singlepiece of metal or other desirable composite. In some embodiments, thebody 702 of the chain ring 700 may be formed by machining, punching, orother suitable method. In some embodiments, the body 702 may be made ofmore than one piece, and the pieces joined together, for example, bywelding or sintering. The body may then be placed on a rotating jig andthe sides of the teeth 704 may be tapered by abrading the sides of theteeth to form a taper (not shown in this embodiment) on each side of thechain ring. The teeth shapes may then be machined in any conventionalmanner.

In many embodiments, it may be desirable for the chain ring teeth to begenerally laterally symmetrical. For example, in many embodiments, thefirst tooth 500 and either the fourth tooth 506 or the fifth tooth 508(or both) may be mirror images of each other. As may be seen in FIGS. 9and 10, the cross-sectional shape of the first tooth 500 (FIG. 10) andthe fifth tooth 508 (FIG. 9) may be generally hat-shaped. In manyembodiments, each tooth may have an end face, such as the end face 510of the first tooth 500 (see FIG. 5). Each end face may be rectangular.Each end face may have a centerpoint, like centerpoint 512 of the endface 510 of the first tooth 500.

The operation of the device as a whole may be understood more clearly inreference to FIG. 16. In many embodiments, the chain ring 700 may beconfigured to engage a crank shaft 1602 in a conventional manner. As theuser pedals, the crank shaft 1602 turns and rotates the chain ring 700,thereby engaging and driving the chain 150. In one embodiment, the chainring 700 is a single chain ring. However, in other embodiments, thechain ring 700 may be one of a series of two or more chain rings. Theteeth 704 of each chain ring 700 are configured to serially engage theconnected links in the chain 150 without the chain shifting betweenrings or between rows of serially arranged teeth 704. That is, when thechain ring 700 is rotated about its axis, the serially-arranged teeth704 engage the serially connected links in the chain 150 mounted thereonas long as the chain ring 700 is rotated and the chain 150 remainsengaged on the teeth 704. Further details of the operation will bediscussed after the discussion of the schematics of the variousembodiments.

Turning now to the schematics of FIGS. 11-15, 28, and 29, it may beobserved that each schematic shows a series of spaced vertical lines.Each series of spaced vertical lines shows vertical lines in one of atleast three lateral positions across a width or thickness of the chainring. These vertical lines are symbolic representations of the end facesof the teeth of a given chain ring. The lines are shown as beingsubstantially the same shape and size as one another. However, the endfaces of the teeth of any given chain ring may differ in size and shapefrom one another. In addition, the lateral space between the teethcompared to the width of the end face as depicted may be exaggerated andnot to scale. A person having ordinary skill in the art will recognizethat these schematics are used to demonstrate a general spatialrelationship between the end faces of the teeth for illustration, not asa precise, detailed location of each tooth. In addition, a person havingordinary skill in the art will understand that for each patternillustrated, that pattern may repeat around the circumference of anygiven chain ring (usually having between 32 and 48 teeth).Alternatively, a chain ring may instead use alternating patterns ofthose illustrated. A person having ordinary skill in the art will beable to select an appropriate pattern or series of patterns to use in agiven chain ring application. Finally, while the schematics may show aperfect alignment and spacing of the end faces of the teeth, a person ofordinary skill in the art will understand that manufacturing tolerancesand material limitations may allow for some variation in tooth placementalong a circumference and a thickness of the chain ring. Thesevariations in placement may be expected and are understood as beingencompassed within the specification and claims of this disclosure, withor without the use of the term “substantially” in each instance.

In addition, a width of a chain ring may be understood to be a thicknessof a chain ring. As will be understood by any person of ordinary skillin the art, the thickness or width of the chain ring may vary atdifferent portions. When the disclosure talks about a lateral positionor position across the width or thickness of one or more teeth, it willbe apparent to a person having ordinary skill in the art that a width orthickness at a circumference of the body, at a position where the teethand/or the spaces between the teeth generally end, is the relevantlocation of the width or thickness for purposes of the presentdisclosure.

Turning first to the pattern illustrated in FIG. 11, the patternillustrated may be described as a regular, repeating pattern of fourteeth. A first tooth 1102 may be positioned at a first lateral position1101 across a thickness 1180 of a chain ring. A second tooth 1104 may bepositioned at a second lateral position 1103 across the thickness 1180of the chain ring. A third tooth 1106 may be positioned at a thirdlateral position 1105 across the thickness 1180 of the chain ring. Thesecond tooth 1104 may be circumferentially between and circumferentiallyadjacent each of the first tooth 1102 and the third tooth 1106. A fourthtooth 1108 may be positioned at the second lateral position 1103 acrossthe thickness 1180 of the chain ring. The pattern defined by the firsttooth 1102, the second tooth 1104, the third tooth 1106, and the fourthtooth 1108 may be seen as repeating through each additional set of fourteeth. For example, a fifth tooth 1110 may be positioned at the firstlateral position 1101. A sixth tooth 1112 may be positioned at thesecond lateral position 1103. The seventh tooth 1114 may be positionedat the third lateral position 1105. The eighth tooth 1116 may bepositioned at the second lateral position 1103. Finally, a ninth tooth1118 may be positioned at the first lateral position 1101. As may beobserved, the first lateral position 1101, the second lateral position1103, and the third lateral position 1105 may differ from one another.The second lateral position 1103 may be laterally between the firstlateral position 1101 and the third lateral position 1105. The spacingbetween the first and second positions may be the same as, or differentfrom, the spacing between the second and third positions. The teeth ofthe chain ring may be thus serially spaced and occupy uniquecircumferential positions that no other tooth occupies. Moreover, eachcircumferentially uniquely-located tooth may occupy one of multiplelateral positions across the thickness of the chainring, and multiplecircumferentially-spaced teeth may occupy the same lateral position.

It may be observed that because the pattern is a repeating pattern offour teeth, the pattern may be expressed as starting at any one toothand ending at the fourth tooth therefrom. For example, the pattern maybe expressed as beginning at the first tooth 1102 and ending at thefourth tooth 1108, as beginning at the second tooth 1104 and ending atthe fifth tooth 1110, as beginning at the third tooth 1106 and ending atthe sixth tooth 1112, or starting at the fourth tooth 1108 and ending atthe seventh tooth 1114. In each instance, the series of four teeth maybe described as a repeating pattern.

The first tooth 1102, the fifth tooth 1110, and the ninth tooth 1118 mayeach be positioned at the first lateral position. Three teeth, namely,the second tooth 1104, the third tooth 1106, and the fourth tooth 1108may be circumferentially between the first tooth 1102 and the fifthtooth 1110. Similarly, three teeth, namely, the sixth tooth 1112, theseventh tooth 1114, and the eighth tooth 1116 may be circumferentiallybetween the fifth tooth 1110 and the ninth tooth 1118. As may beobserved, of the three teeth between respective sets of the two teeth inthe first lateral position, two may be positioned in the second lateralposition and one tooth may be positioned in the third lateral position.The tooth in the third lateral position may be circumferentially betweenthe two teeth in the second lateral position. For example, the firsttooth 1102 and the fifth tooth 1110 may be each positioned in the firstlateral position 1101. Two teeth, namely, the second tooth 1104 and thefourth tooth 1108 may be both positioned at the second lateral positionand may be circumferentially between the first tooth 1102 and the fifthtooth 1110. One tooth, namely, the third tooth 1106, may be positionedat the third lateral position 1105 and may be immediatelycircumferentially between the second tooth 1104 and the fourth tooth1108 and may also be circumferentially between the first tooth 1102 andthe fifth tooth 1110.

As may further be seen in FIG. 11, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 11 by the dashed line 1130. In theembodiment of FIG. 11, the substantially undulating pattern is atriangle wave.

In the embodiment of FIG. 11, some of the centerpoints of the tooth endfaces may be seen as being positioned at a peak or valley of thesubstantially undulating pattern 1130. Others of the centerpoints of thetooth end faces may be seen as being positioned away from a peak orvalley of the substantially undulating pattern 1130. For example, afirst centerpoint 1132, a second centerpoint 1138, and a thirdcenterpoint 1142 may each be seen as being positioned at respectivevalleys of the substantially undulating pattern 1130. A fourthcenterpoint 1136 and a fifth centerpoint 1140 may each be seen as beingpositioned at respective peaks of the substantially undulating pattern1130. A sixth centerpoint 1142, a seventh centerpoint 1144, an eighthcenterpoint 1146, and a ninth centerpoint 1148 may each be seen as beingpositioned away from either a peak or a valley of the substantiallyundulating pattern 1130.

In the embodiment of FIG. 11, because the substantially undulatingpattern 1130 may be regular around a circumference of the chain ring,there may be a predictable proportion of the teeth that are positionedat each lateral position. In the embodiment of FIG. 11, a quarter of theteeth may be positioned at the first lateral position 1101, a quarter ofthe teeth may be positioned at the third lateral position 1105, and halfthe teeth may be positioned at the second lateral position.

The embodiment of FIG. 11 may be most suitable in configurations wherethe chain ring has a number of teeth that is divisible by four, i.e.,32, 36, 40, or 44. The regular four-tooth pattern of FIG. 11 is unlikelyto be used on a chain ring that includes a number of teeth not divisibleby four. This is because the precise regularity of the pattern may bebroken when the number of teeth is not divisible by four.

A detailed chain ring showing another possible embodiment of the chainring of FIG. 11 is shown in FIGS. 18-22. The embodiment shown in FIGS.18-22 is of a chain ring that includes 32 teeth. Accordingly the numberof teeth is divisible by four and can be formed into the regularundulating pattern shown in FIG. 11. The side views of the embodimentsshown in FIGS. 18 and 22 are taken from the “outboard” side of the chainring. It will be apparent to a person having ordinary skill in the artthat the opposite side of the chain ring may substantially be a mirrorimage of the side shown in FIGS. 18 and 22. Accordingly, the toothpattern shown in FIG. 11 may instead be shown as a mirror image,depending on which way the chain ring is oriented or held. This aspectof the FIGS. will be apparent to a person having ordinary skill in theart.

Turning first to FIG. 18, the chain ring 1800 may include a body 1802and a plurality of teeth 1804 circumferentially affixed or affixedaround a circumference 1806 of the body 1802. The teeth 1804 in thisembodiment may be discussed in the disclosure as being positionedcircumferentially with respect to one another. A first tooth 1808 may becircumferentially spaced from a second tooth 1810. In the embodimentdisclosed in FIG. 18, the first tooth 1808 and the second tooth 1810 maybe described as having three teeth, specifically the third tooth 1812,the fourth tooth 1814, and the fifth tooth 1816, circumferentiallybetween the first tooth 1808 and the second tooth 1810. Similarly, thethird tooth 1812 may be described as being circumferentially adjacentthe first tooth 1808 and the fourth tooth 1814. When discussing anytooth 1804 circumferentially with respect to any other tooth 1804, thelateral position, i.e., the position of the tooth 1804 along or across athickness of the chain ring body 1802 is not important.

In some embodiments, the chain ring 1800 may be machined from a singlepiece of metal or other desirable composite. In some embodiments, thebody 1802 of the chain ring 1800 may be formed by machining, punching,or other suitable method. In some embodiments, the body 1802 may be madeof more than one piece, and the pieces joined together, for example, bywelding or sintering. The body may then be placed on a rotating jig andthe sides of the teeth 1804 may be tapered by abrading the sides of theteeth to form a taper on each side of the chain ring. Only one side ofthe chain ring 1800 is shown, so only one side of the taper 1813 isshown in FIG. 18. The teeth shapes may then be machined in anyconventional manner.

Turning to FIGS. 19-21, the taper and tooth shape may be more clearlyshown. Each of FIGS. 19-21 shows a cross-section of the tooth along aline that is a radius, diameter, or portion thereof across the chainring 1800. Turning first to FIG. 19, there is shown a cross section of atooth having a configuration substantially similar or identical to firsttooth 1808 and second tooth 1810. As shown in FIG. 19, a representativefirst inboard tooth 1908 and a representative second inboard tooth 1910may each be attached at a first lateral position 1909 along a thickness1911 of the body 1802 of the chain ring 1800. Each of the inboard teeth1908, 1910 may have a generally trapezoidal cross-sectional shape alongthis line. Each of these teeth 1908, 1910 may have a generallyhat-shaped cross section (like that shown in FIG. 9) when taken along across-sectional line perpendicular to the cross-section taken (aperpendicular cross-sectional line). As shown in FIG. 19, each of theinboard teeth 1908, 1910 may have a taper 1913, 1915, respectively, thatmay cause each of the inboard teeth 1908, 1910 to taper to a line 1917,1919, respectively. Each of the tapered surfaces 1913, 1915 mayrepresent an end face of the respective tooth 1908, 1910 and may besubstantially rectangular, as may be better seen in FIG. 18.

FIG. 20 shows a cross-sectional view of a representative outboard tooth2014, having a configuration substantially similar or identical to theoutboard tooth 1814 shown in FIG. 18. The cross-section of FIG. 20 issimplified and includes only the tooth on one side of the chain ring1800. A person having ordinary skill in the art will understand that afull-cross section would demonstrate more clearly that anyrepresentative outboard tooth may be a mirror image of anyrepresentative inboard tooth, as may be observed through a comparison ofFIGS. 19 and 20. As shown in FIG. 20, a representative first outboardtooth 2014 may be attached at a third lateral position 2021 along athickness 1911 of the body 1802 of the chain ring 1800. Each outboardtooth 2014 may have a generally trapezoidal cross-sectional shape alongthis line. Each outboard tooth 2014 may have a generally hat-shapedcross section (like that shown in FIG. 10) when taken along aperpendicular cross-sectional line. As shown in FIG. 20, each outboardtooth 2014 may have a tapered surface 2023 that may cause each of theoutboard teeth 2014 to taper to a line 2025. Each tapered surface 2023may represent an end face of the outboard tooth 2014 and may besubstantially rectangular, as may be better seen in FIG. 18.

FIG. 21 shows a cross-sectional view of a representative middle tooth2112, having a configuration substantially similar or identical toeither the middle tooth 1812 or the middle tooth 1816 shown in FIG. 18.The cross-section of FIG. 21 is simplified and includes only the toothon one side of the chain ring 1800. As shown in FIG. 21, arepresentative middle tooth 2112 may be attached at a second lateralposition 2127 along a thickness 1911 of the body 1802 of the chain ring1800. Each middle tooth 2112 may have a generally rectangularcross-sectional shape with one pointed end along this line. Each middletooth 2112 may have a generally rectangular cross section when takenalong a perpendicular cross-sectional line. As shown in FIG. 21, eachmiddle tooth 2112 may have an outboard tapered surface 2129 and aninboard tapered surface 2131 that may cause each of the middle teeth2112 to taper to a line 2133. The combined tapered surfaces 2129, 2131may represent an end face of the middle tooth 2112 and may besubstantially rectangular, as may be better seen in FIG. 18.

The above description of the configuration, shapes, and tapers of theteeth described in FIGS. 18-21 may be somewhat simplified. Turning toFIG. 22, a more detailed view of the teeth may be seen. As shown in FIG.22, when the shapes of the teeth 1804 are machined, there may bediscontinuities introduced in to the outer periphery of each tooth 1804.As an example, a representative inboard tooth 1908 may not have aprecisely rectangular tapered end face 1915. Instead, the end face mayinclude various angled portions that appear more tree-shaped upon closerexamination. However, such a configuration may fall within thedefinition of a substantially rectangular shape. Similar discontinuitiesmay be present for any representative middle tooth 2112 and outboardtooth 2014. Precise configuration details may differ according to thedesires of any person having ordinary skill in the art.

Turning now to FIG. 12, a configuration of teeth that may be added orsubstituted for the embodiment of FIG. 11 may be seen. In the embodimentof FIG. 12, a repeating pattern of teeth in a second lateral position isadded. Such a repeating pattern may be used if, for example, a chainring is used that has an even number of teeth that is not divisible byfour, i.e., 34, 38, 42, or 46. In such a configuration, the addition oftwo teeth in the second lateral position may be desirable. Of course, aperson having ordinary skill in the art may elect to add a repeatingpattern of teeth in the second lateral position in any position alongthe chain ring. Indeed, in a conventional chain ring, all the teeth maybe considered to be in a middle, or second, lateral position. In manyways, the position of the teeth in FIG. 12 is similar to that in FIG.11.

A first tooth 1202 may be positioned at a first lateral position 1201across a thickness 1280 of a chain ring. A second tooth 1204 may bepositioned at a second lateral position 1203 across the thickness 1280of the chain ring. A third tooth 1206 may be positioned at a thirdlateral position 1205 across the thickness 1280 of the chain ring. Thesecond tooth 1204 may be circumferentially between and circumferentiallyadjacent each of the first tooth 1202 and the third tooth 1206. A fourthtooth 1208 may be positioned at the second lateral position 1203 acrossthe thickness 1280 of the chain ring. After the fourth tooth 1208, thefour-tooth pattern may be seen as being broken. Instead, a fifth tooth1210 and a sixth tooth 1212 may be positioned at the second lateralposition 1203 circumferentially adjacent the fourth tooth 1208. Thepattern defined by the first tooth 1202, the second tooth 1204, thethird tooth 1206, and the fourth tooth 1208 may be seen as thenrepeating through each additional set of four teeth. For example, aseventh tooth 1214 may be positioned at the first lateral position 1201.An eighth tooth 1216 may be positioned at the second lateral position1203. The ninth tooth 1218 may be positioned at the third lateralposition 1205. The tenth tooth 1220 may be positioned at the secondlateral position 1203. Finally, an eleventh tooth 1222 may be positionedat the first lateral position 1201. As may be observed, the firstlateral position 1201, the second lateral position 1203, and the thirdlateral position 1205 may differ from one another. The second lateralposition 1203 may be laterally between the first lateral position 1201and the third lateral position 1205. The spacing between the first andsecond positions may be the same as, or different from, the spacingbetween the second and third positions.

The first tooth 1202, the seventh tooth 1214, and the eleventh tooth1222 may each be positioned at the first lateral position. Five teeth,namely, the second tooth 1204, the third tooth 1206, the fourth tooth1208, the fifth tooth 1210, and the sixth tooth 1212 may becircumferentially between the first tooth 1202 and the seventh tooth1214. Similarly, three teeth, namely, the eighth tooth 1216, the ninthtooth 1218, and the tenth tooth 1220 may be circumferentially betweenthe seventh tooth 1214 and the eleventh tooth 1222. As may be observed,of the teeth disposed circumferentially between the two closest teeth inthe first lateral position 1201, at least two of the teeth may bepositioned in the second lateral position 1203 and one tooth may bepositioned in the third lateral position 1205. The tooth in the thirdlateral position 1205 may be circumferentially between the two teeth inthe second lateral position 1203. For example, first tooth 1202 and theseventh tooth 1214 may be each positioned in the first lateral position1201. Four teeth, namely, second tooth 1204, fourth tooth 1208, fifthtooth 1210, and sixth tooth 1212 may each be positioned at the secondlateral position and may be circumferentially between the first tooth1202 and the seventh tooth 1214. One tooth, namely, third tooth 1206,may be positioned at the third lateral position 1205 and may becircumferentially between the second tooth 1204 and the fourth tooth1208 and may be circumferentially between the first tooth 1202 and theseventh tooth 1214.

As may further be seen in FIG. 12, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 12 by the dashed line 1230.

In the embodiment of FIG. 12, some of the centerpoints of the tooth endfaces may be seen as being positioned at a peak or valley of thesubstantially undulating pattern 1230. Others of the centerpoints of thetooth end faces may be seen as being positioned away from a peak orvalley of the substantially undulating pattern 1230. For example, afirst centerpoint 1232, a second centerpoint 1246, and a thirdcenterpoint 1254 may each be seen as being positioned at respectivevalleys of the substantially undulating pattern 1230. A fourthcenterpoint 1236 and a fifth centerpoint 1250 may each be seen as beingpositioned at respective peaks of the substantially undulating pattern1230. A sixth centerpoint 1234, a seventh centerpoint 1238, an eighthcenterpoint 1240, a ninth centerpoint 1244, a tenth centerpoint 1248,and an eleventh centerpoint 1252 may each be seen as being positionedaway from either a peak or valley of the substantially undulatingpattern 1230.

In the embodiment of FIG. 12, because the substantially undulatingpattern 1230 may have a generally consistent pattern around acircumference of the chain ring, there may be a predictable proportionof the teeth that are positioned at each lateral position. In theembodiment of FIG. 12, about a quarter of the teeth may be positioned atthe first lateral position 1201, about a quarter of the teeth may bepositioned at the third lateral position 1205, and just over half theteeth may be positioned at the second lateral position 1203. If thepattern of repeated teeth in the second lateral position (like the teeth1210 and 1212) is included more than once around the circumference ofthe chain ring, the proportion of teeth in the second lateral position1203 may be increased and that the proportion of teeth in each of thefirst lateral position 1201 and the third lateral position 1205 may bedecreased. However, at least half the teeth in such a configuration maybe positioned in the second lateral position.

A detailed chain ring showing one possible embodiment of the chain ringof FIG. 12 is shown in FIGS. 23-27. The embodiment shown in FIGS. 23-27is of a chain ring that includes 34 teeth. Accordingly the number ofteeth is not divisible by four and cannot be formed into the regularundulating pattern shown in FIG. 11. Instead, two additional middleteeth are included, like the configuration shown in FIG. 12. Thisrepeated middle tooth is shown in the area marked generally as 2350 inFIGS. 23 and 27. The side views of the embodiments shown in FIGS. 23 and27 are taken from the “outboard” side of the chain ring. It will beapparent to a person having ordinary skill in the art that the oppositeside of the chain ring may substantially be a mirror image of the sideshown in FIGS. 23 and 27. Accordingly, the tooth pattern shown in FIG.12 may instead be shown as a mirror image, depending on which way thechain ring is oriented or held. This aspect of the FIGS. will beapparent to a person having ordinary skill in the art.

Turning first to FIG. 23, the chain ring 2300 may include a body 2302and a plurality of teeth 2304 circumferentially affixed or affixedaround a circumference 2306 of the body 2302. The teeth 2304 in thisembodiment may be discussed in the disclosure as being positionedcircumferentially with respect to one another. A first tooth 2308 may becircumferentially spaced from a second tooth 2310. In the embodimentdisclosed in FIG. 23, the first tooth 2308 and the second tooth 2310 maybe described as having five teeth, specifically the third tooth 2312,the fourth tooth 2314, the fifth tooth 2316, the sixth tooth 2318, andthe seventh tooth 2320, circumferentially between the first tooth 2308and the second tooth 2310. Similarly, the third tooth 2312 may bedescribed as being circumferentially adjacent the first tooth 2308 andthe fourth tooth 2314. When discussing any tooth 2304 circumferentiallywith respect to any other tooth 2304, the lateral position, i.e., theposition of the tooth 2304 along or across a thickness of the chain ringbody 2302 is not important.

In some embodiments, the chain ring 2300 may be machined from a singlepiece of metal or other desirable composite. In some embodiments, thebody 2302 of the chain ring 2300 may be formed by machining, punching,or other suitable method. In some embodiments, the body 2302 may be madeof more than one piece, and the pieces joined together, for example, bywelding or sintering. The body may then be placed on a rotating jig andthe sides of the teeth 2304 may be tapered by abrading the sides of theteeth to form a taper on each side of the chain ring. Only one side ofthe chain ring 2300 is shown, so only one side of the taper 2313 isshown in FIG. 23. The teeth shapes may then be machined in anyconventional manner.

Turning to FIGS. 24-26, the taper and tooth shape may be more clearlyshown. Each of FIGS. 24-26 shows a cross-section of the tooth along aline that is a radius, diameter, or portion thereof across the chainring 2300. Turning first to FIG. 24, there is shown a cross section of atooth having a configuration substantially similar or identical to firsttooth 2308 and second tooth 2310. As shown in FIG. 24, a representativefirst inboard tooth 2408 may be attached at a first lateral position2409 along a thickness 2411 of the body 2302 of the chain ring 2300.Each inboard tooth 2308 may have a generally trapezoidal cross-sectionalshape along this line. Each inboard tooth 2308 may have a generallyhat-shaped cross section (like that shown in FIG. 9) when taken along aperpendicular cross-sectional line. As shown in FIG. 24, each of theinboard teeth 2408 may have a tapered surface 2413 that may cause eachof the inboard teeth 2408 to taper to a line 2417. Each of the taperedsurfaces 2413 may represent an end face of the respective inboard tooth2408 and may be substantially rectangular, as may be better seen in FIG.23. It is noted that because the number of teeth on the chain ring shownin FIG. 23-27 is not divisible by 4, the teeth on opposite sides of thechain ring may not share the same cross-sectional shape, unlike theembodiment of FIGS. 18-22.

FIG. 25 shows a cross-sectional view of a representative outboard tooth2518, having a configuration substantially similar or identical to theoutboard tooth 2318 shown in FIG. 23. The cross-section of FIG. 25 issimplified and includes only the tooth on one side of the chain ring2300. A person having ordinary skill in the art will understand that afull-cross section would demonstrate more clearly that anyrepresentative outboard tooth may be a mirror image of anyrepresentative inboard tooth, as may be seen in a comparison of FIGS. 24and 25. As shown in FIG. 25, a representative first outboard tooth 2518may be attached at a third lateral position 2521 along a thickness 2411of the body 2302 of the chain ring 2300. Each outboard tooth 2518 mayhave a generally trapezoidal cross-sectional shape along this line. Eachoutboard tooth 2518 may have a generally hat-shaped cross section (likethat shown in FIG. 10) when taken along a perpendicular cross-sectionalline. As shown in FIG. 25, each outboard tooth 2518 may have a taperedsurface 2523 that may cause each of the outboard teeth 2518 to taper toa line 2525. Each tapered surface 2523 may represent an end face of theoutboard tooth 2518 and may be substantially rectangular, as may bebetter seen in FIG. 23.

FIG. 26 shows a cross-sectional view of a representative middle tooth2612, having a configuration substantially similar or identical to themiddle tooth 2312, the middle tooth 2314, the middle tooth 2316, or themiddle tooth 2320 shown in FIG. 20. The cross-section of FIG. 26 issimplified and includes only the tooth on one side of the chain ring2300. As shown in FIG. 26, a representative middle tooth 2612 may beattached at a second lateral position 2627 along a thickness 2411 of thebody 2302 of the chain ring 2300. Each middle tooth 2612 may have agenerally rectangular cross-sectional shape with one pointed end in thecross-section taken along this line. Each middle tooth 2612 may have agenerally rectangular cross section when taken along a perpendicularcross-sectional line. As shown in FIG. 26, each middle tooth 2612 mayhave an outboard tapered surface 2629 and an inboard tapered surface2631 that may cause each of the middle teeth 2612 to taper to a line2633. The combined tapered surfaces 2629, 2631 may represent an end faceof the middle tooth 2612 and may be substantially rectangular, as may bebetter seen in FIG. 23.

The above description of the configuration, shapes, and tapers of theteeth described in FIGS. 23-26 may be somewhat simplified. Turning toFIG. 27, a more detailed view of the teeth may be seen. As shown in FIG.27, when the shapes of the teeth 2304 are machined, cast, or otherwiseformed, there may be discontinuities introduced in to the outerperiphery of each tooth 2304. As an example, a representative inboardtooth 2408 may not have a precisely rectangular tapered end face 2415.Instead, the end face may include various angled portions that appearmore tree-shaped upon closer examination. However, such a configurationmay fall within the definition of a substantially rectangular shape.Similar discontinuities may be present for any representative middletooth 2612 and outboard tooth 2518. Precise configuration details maydiffer according to the desires of any person having ordinary skill inthe art.

Turning now to FIG. 13, an exaggerated version of the embodiment of FIG.12 may be found. In the embodiment of FIG. 13, a larger plurality ofteeth is located in the second lateral position than in the embodimentof FIG. 12. A person having ordinary skill in the art may elect toinclude such a design if they feel that a run of teeth in the secondlateral position is desirable for any reason.

A first tooth 1302 may be positioned at a first lateral position 1301across a thickness 1380 of a chain ring. A second tooth 1304 may bepositioned at a second lateral position 1303 across the thickness 1380of the chain ring. A third tooth 1306 may be positioned at a thirdlateral position 1305 across the thickness 1380 of the chain ring. Thesecond tooth 1304 may be circumferentially between and circumferentiallyadjacent each of the first tooth 1302 and the third tooth 1306. A fourthtooth 1308 may be positioned at the second lateral position 1303 acrossthe thickness 1380 of the chain ring. After the fourth tooth 1308, thefour-tooth pattern may be seen as being broken. Instead, a fifth tooth1310, a sixth tooth 1312, a seventh tooth 1314, and an eighth tooth 1316may be positioned at the second lateral position circumferentiallyadjacent the fourth tooth 1308. The pattern defined by the first tooth1302, the second tooth 1304, the third tooth 1306, and the fourth tooth1308 may be seen as then repeating through each additional set of fourteeth. For example, a ninth tooth 1318 may be positioned at the firstlateral position 1301. A tenth tooth 1320 may be positioned at thesecond lateral position 1303. An eleventh tooth 1322 may be positionedat the third lateral position 1305. Finally, a twelfth tooth (not shown)may be positioned at the second lateral position 1303. As may beobserved, the first lateral position 1301, the second lateral position1303, and the third lateral position 1305 may differ from one another.The second lateral position 1303 may be laterally between the firstlateral position 1301 and the third lateral position 1305. The spacingbetween the first and second positions may be the same as, or differentfrom, the spacing between the second and third positions.

The first tooth 1302 and the ninth tooth 1318 may each be positioned atthe first lateral position 1301. Seven teeth, namely, the second tooth1304, the third tooth 1306, the fourth tooth 1308, the fifth tooth 1310,the sixth tooth 1312, the seventh tooth 1314, and the eighth tooth 1316may be circumferentially between the first tooth 1302 and the ninthtooth 1318. As may be observed, of the teeth disposed circumferentiallybetween the two closest teeth in the first lateral position, at leasttwo of the teeth may be positioned in the second lateral position 1303and one tooth may be positioned in the third lateral position 1305. Thetooth in the third lateral position 1305 may be circumferentiallybetween the two teeth in the second lateral position 1303. For example,the first tooth 1302 and the ninth tooth 1318 may be each positioned inthe first lateral position 1301. Six teeth, namely, second tooth 1304,fourth tooth 1308, fifth tooth 1310, sixth tooth 1312, seventh tooth1314, and eighth tooth 1316 may each be positioned at the second lateralposition and may be circumferentially between the first tooth 1302 andthe seventh tooth 1314. One tooth, namely, third tooth 1306, may bepositioned at the third lateral position 1305 and may becircumferentially immediately between the second tooth 1304 and thefourth tooth 1308 and may also be circumferentially between the firsttooth 1302 and the ninth tooth 1318.

As may further be seen in FIG. 13, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 13 by the dashed line 1330.

In the embodiment of FIG. 13, some of the centerpoints of the tooth endfaces may be seen as being positioned at a peak or valley of thesubstantially undulating pattern 1330. Others of the centerpoints of thetooth end faces may be seen as being positioned away from a peak orvalley of the substantially undulating pattern 1330. For example, afirst centerpoint 1332 and a second centerpoint 1348 may each be seen asbeing positioned at respective valleys of the substantially undulatingpattern 1330. A third centerpoint 1336 and a fourth centerpoint 1352 mayeach be seen as being positioned at respective peaks of thesubstantially undulating pattern 1330. A fifth centerpoint 1334, a sixthcenterpoint 1338, a seventh centerpoint 1340, an eighth centerpoint1342, a ninth centerpoint 1344, a tenth centerpoint 1346, and aneleventh centerpoint 1350 may each be seen as being positioned away fromeither a peak or valley of the substantially undulating pattern 1330.

In the embodiment of FIG. 13, because the substantially undulatingpattern 1330 may have a generally consistent pattern around acircumference of the chain ring, there may be a predictable proportionof the teeth that are positioned at each lateral position. In theembodiment of FIG. 13, somewhat less than about a quarter of the teethmay be positioned at the first lateral position 1301, somewhat less thanabout a quarter of the teeth may be positioned at the third lateralposition 1305, and just over half the teeth may be positioned at thesecond lateral position 1303. If the pattern of repeated teeth in thesecond lateral position (like the teeth 1310, 1312, 1314, and 1316) isincluded more than once around the circumference of the chain ring, theproportion of teeth in the second lateral position 1303 may be increasedand the proportion in each of the first lateral position 1301 and thethird lateral position 1305 may be decreased. However, at least half theteeth in such a configuration may be positioned in the second lateralposition.

Turning now to FIG. 14, a person having ordinary skill in the art mayselect a repeating pattern of a tooth in one of the first or thirdlateral position followed by a tooth in the second lateral position.Such a pattern may be used if, for example, a chain ring is used thathas an even number of teeth that is not divisible by four, i.e., 34, 38,42, or 46. In such a configuration, the addition of two teeth, one eachin the second lateral position and in one of the first or third lateralposition may be desirable. Of course, a person having ordinary skill inthe art may elect to add such a pattern of teeth in any position alongthe chain ring.

A first tooth 1402 may be positioned at a first lateral position 1401across a thickness 1480 of a chain ring. A second tooth 1404 may bepositioned at a second lateral position 1403 across the thickness 1480of the chain ring. A third tooth 1406 may be positioned at a thirdlateral position 1405 across the thickness 1480 of the chain ring. Thesecond tooth 1404 may be circumferentially between and circumferentiallyadjacent each of the first tooth 1402 and the third tooth 1406. A fourthtooth 1408 may be positioned at the second lateral position 1403 acrossthe thickness 1480 of the chain ring. After the fourth tooth 1408, thefour-tooth pattern may be seen as being broken. Instead, a fifth tooth1410 may be positioned at the third lateral position 1405 and a sixthtooth 1412 may be positioned at the second lateral position 1403. In analternative embodiment (not shown), the fifth tooth may be positionedinstead at the first lateral position 1401 instead of the third lateralposition 1405. The pattern defined by the first tooth 1402, the secondtooth 1404, the third tooth 1406, and the fourth tooth 1408 may be seenas then repeating through each additional set of four teeth. Forexample, a seventh tooth 1414 may be positioned at the first lateralposition 1401. An eighth tooth 1416 may be positioned at the secondlateral position 1403. A ninth tooth 1418 may be positioned at the thirdlateral position 1405. A tenth tooth 1420 may be positioned at thesecond lateral position 1403. Finally, an eleventh tooth 1422 may bepositioned at the first lateral position 1401. As may be observed, thefirst lateral position 1401, the second lateral position 1403, and thethird lateral position 1405 may differ from one another. The secondlateral position 1403 may be laterally between the first lateralposition 1401 and the third lateral position 1405. The spacing betweenthe first and second positions may be the same as, or different from,the spacing between the second and third positions.

The first tooth 1402, the seventh tooth 1414, and the eleventh tooth1422 may each be positioned at the first lateral position. Five teeth,namely, the second tooth 1404, the third tooth 1406, the fourth tooth1408, the fifth tooth 1410, and the sixth tooth 1412 may becircumferentially between the first tooth 1402 and the seventh tooth1414. Similarly, three teeth, namely, the eighth tooth 1416, the ninthtooth 1418, and the tenth tooth 1420 may be circumferentially betweenthe seventh tooth 1414 and the eleventh tooth 1422. As may be observed,of the teeth disposed circumferentially between the two closest teeth inthe first lateral position 1401, at least two of the teeth may bepositioned in the second lateral position 1403 and at least one toothmay be positioned in the third lateral position 1405. Each tooth in thethird lateral position 1405 may be circumferentially between the twoteeth in the second lateral position 1403. For example, first tooth 1402and the seventh tooth 1414 may be each positioned in the first lateralposition 1401. Three teeth, namely, second tooth 1404, fourth tooth1408, and sixth tooth 1412 may each be positioned at the second lateralposition and may be circumferentially between the first tooth 1402 andthe seventh tooth 1414. Two teeth, namely, third tooth 1406 and fifthtooth 1410, may be positioned at the third lateral position 1405 and mayeach be circumferentially between two teeth in the second lateralposition. The third tooth 1406 may be positioned between the secondtooth 1404 and the fourth tooth 1408 and may be circumferentiallybetween the first tooth 1402 and the seventh tooth 1414. The fifth tooth1410 may be positioned circumferentially immediately between the fourthtooth 1408 and the sixth tooth 1412 and also may be circumferentiallybetween the first tooth 1402 and the seventh tooth 1414.

As may further be seen in FIG. 14, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 14 by the dashed line 1430.

In the embodiment of FIG. 14, some of the centerpoints of the tooth endfaces may be seen as being positioned at a peak or valley of thesubstantially undulating pattern 1430. Others of the centerpoints of thetooth end faces may be seen as being positioned away from a peak orvalley of the substantially undulating pattern 1430. For example, afirst centerpoint 1432, a second centerpoint 1444, and a thirdcenterpoint 1452 may each be seen as being positioned at respectivevalleys of the substantially undulating pattern 1430. A fourthcenterpoint 1436, a fifth centerpoint 1440, and a sixth centerpoint 1448may each be seen as being positioned at respective peaks of thesubstantially undulating pattern 1430. A seventh centerpoint 1434, aneighth centerpoint 1438, a ninth centerpoint 1442, a tenth centerpoint1446, and an eleventh centerpoint 1450 may each be seen as beingpositioned away from either a peak or valley of the substantiallyundulating pattern 1430.

In the embodiment of FIG. 14, because the substantially undulatingpattern 1430 may have a generally consistent pattern around acircumference of the chain ring, there may be a predictable proportionof the teeth that are positioned at each lateral position. In theembodiment of FIG. 14, about a quarter of the teeth may be positioned atthe first lateral position 1401, about a quarter of the teeth may bepositioned at the third lateral position 1405, and about half the teethmay be positioned at the second lateral position 1403. If the pattern ofteeth in the two tooth pattern (like the teeth 1410 and 1412) isincluded more than once around the circumference of the chain ring, andif that pattern disproportionately uses a tooth (like tooth 1410) in oneor the other of the first lateral position 1401 or the third lateralposition 1405, the proportion of teeth in that lateral position may beincreased and the proportion in the other of the first lateral position1401 or the third lateral position 1405 may be decreased. However, atleast half the teeth in such a situation may be positioned in the secondlateral position 1403.

The embodiment of FIG. 15 illustrates an alternative embodiment of toothshape. While certain tooth shapes have been illustrated and describedherein, these tooth shapes may be modified by a person having ordinaryskill in the art to provide different aesthetic and/or functionalfeatures. For example, the embodiment of FIG. 15 illustrates one suchembodiment. In the illustrated embodiment, the substantially undulatingpattern 1530 between the teeth is more curved in a sine wave form thanthe triangular wave defined, for example, in FIG. 11. In such anembodiment, a first tooth 1502 and a fifth tooth 1510 in a first lateralposition 1501 across the thickness 1580 of the chain ring may be shapedin a concave manner, with the concavity oriented toward the secondlateral position 1503. A third tooth 1506 in a third lateral position1505 may be shaped in a concave manner, with the concavity orientedtoward the second lateral position 1503. Each of the second tooth 1504and the fourth tooth 1508 may be positioned in the second lateralposition. Each of the teeth in the second lateral position may be angledor canted to provide a more smoothed appearance between the curvedadjacent teeth.

In many of the embodiments, the tooth shape shown is regular andsymmetrical. However, such a tooth shape is not required. Any toothshape thought to be desirable by a designer could be substituted in anyof the embodiments shown. The tooth may instead be configured to be likethat of the tooth 3300 shown in FIG. 33. A person having ordinary skillin the art will understand that the tooth shapes shown in any of theFIGS. are exemplary and not limiting.

Many different tooth appearances may be used and many different endshapes may be used and fall within the scope of the present disclosureand claims. For example, the end faces of the teeth could be stamped orshaped to spell a word, such as a rider's or team's name or logo.Indeed, instead of a curved taper, a sharper angle could be used to givea more aggressive appearance. The examples given are merelyillustrative, however, and a person having ordinary skill in the artwill be able to incorporate known and conceivable shapes into the teethas may be desirable and/or economical for a given application or use.

Turning now to FIG. 17, the function of the various embodiments and howa person having ordinary skill in the art would select among variousones of the embodiments disclosed will be discussed. For purposes ofdiscussion, FIG. 17 illustrates a chain ring having a toothconfiguration represented in the schematic shown in FIG. 11 toillustrate how such a design would function in connection with thechain.

As shown in FIG. 16, the chain ring 700 may have a body 702 and aplurality of teeth 704 affixed around a circumference of the body 702.The teeth 704 may be configured to engage the chain 150 withoutshifting. The interaction of the chain 150 and the teeth 704 may be seenmore clearly in FIG. 17. FIG. 17 shows a chain 150 that has a series ofouter links and inner links as shown in FIG. 1. In order to simplify theview, the details of the manner in which the chain links are attached toone another have been eliminated to focus instead on the relative size,shape, and placement of the teeth and the chain links.

Because the chain 150 is configured to drive a bicycle forwardly, aforward face of each tooth 704 may be configured to engage a forwardside of each chain link when the crank is pedaled to create force. Thismay transmit force to the rear wheel and power the bicycle. In theconfiguration of FIG. 17, some of the teeth 704 may also engage alateral face of a corresponding chain link to impart a lateral force tothe chain 150.

The chain 150 may include a first link 1702, which may be an outer link.The chain ring 700 may include a first tooth 1704, which may bepositioned at a first lateral position 1701 across a thickness 1780 ofthe chain ring 700. The first tooth 1704 may be configured to engage thefirst link 1702 at its first lateral side 1706, thereby imparting aforce to the chain 150 in a first lateral direction 1708. The chain 150may include a second link 1710, which may be an inner link. The chainring 700 may include a second tooth 1712, which may be positioned at asecond lateral position 1703 across a thickness 1780 of the chain ring700. The second tooth 1712 may be configured to fit within the secondlink 1710 without imparting a substantial lateral force to the chain150. The chain 150 may include a third link 1714, which may be an outerlink. The chain ring 700 may include a third tooth 1716, which may bepositioned at a third lateral position 1705 across a thickness 1780 ofthe chain ring 700. The third tooth 1716 may be configured to engage thethird link 1714 at its second lateral side 1718, thereby imparting aforce to the chain 150 in a second lateral direction 1720.

In many of the embodiments disclosed, it was mentioned that the numberof teeth in the first lateral position, such as first lateral position1701, and the third lateral position, such as third lateral position1705 may be about equal and may each be about a quarter of the teeth ongiven chain ring. Keeping the number of teeth in the first lateralposition 1701 and the third lateral position 1703 approximately equalwill lead to the lateral force in the first direction 1708 (the firstlateral force) and the lateral force in the second direction 1720 (thesecond lateral force) to be approximately equal, which may be desirablein many embodiments. When either lateral force is applied to the chain150, the chain 150 is permitted to flex in the direction of therespective lateral force. In many embodiments, the chain is permittedsome lateral give or play due to its construction. The application oflateral force by the embodiments disclosed may provide additionalsecurity to the chain engagement.

In another configuration, the second tooth 1712 may be configured totransmit no net lateral force to the drive chain. For example, thesecond tooth 1712 may transmit substantially equivalent lateral forcesin each of the first direction 1708 and the second direction 1720. Insuch a configuration, where the lateral forces are substantially equal,the second tooth 1712 may be considered as transmitting no lateralforce. Similarly, in other configurations, the chain 150 may becomemisaligned. In such a configuration, the second tooth 1712 may transmita lateral force to the chain 150 to correct such a misalignment, andthen transmit no additional lateral force. Such a temporary applicationof force is also not considered a transmission of force in the contextof the present disclosure.

Attention may also be drawn to the next series of three links and teeth.A fourth link 1746 may be an inner link. A fifth link 1750 may be anouter link. A sixth link 1754 may be an inner link. As may be expected,the fourth tooth 1748 and the sixth tooth 1758 may be positioned in asecond lateral position 1703, and may impart little or no lateral forceto the chain 150. In the illustrated embodiment, the fifth tooth 1752,rather than being positioned in a first lateral position 1701 or a thirdlateral position 1705, is instead positioned in the second lateralposition 1703. A person having ordinary skill in the art will understandthat an outer link of the chain 150 may have an increased width 1760that may allow for a tooth 704 to be placed within the outer link of thechain 150 in any of the three lateral positions. The reduced width 1762of the inner link of the chain 150 may limit the variety of lateralplacements of a given tooth 704, and in many embodiments, may limit itto placement in the second lateral position 1703. A person havingordinary skill in the art may select an appropriate configuration ofteeth given the spacing of a particular drive chain and the width of aparticular chain ring.

In some embodiments, if additional pressure is desired on one or morelinks of a chain, the “second position” can be modified to incorporatetwo, three, or more positions. Such configurations may be seen in FIGS.28 and 29.

Turning first to the pattern illustrated in FIG. 28, the patternillustrated may be described as a regular, repeating pattern of fourteeth. A first tooth 2802 may be positioned at a first lateral position2801 across a thickness 2880 of a chain ring. A second tooth 2804 may bepositioned at a second lateral position 2803 across the thickness 2880of the chain ring. A third tooth 2806 may be positioned at a thirdlateral position 2805 across the thickness 2880 of the chain ring. Thesecond tooth 2804 may be circumferentially between and circumferentiallyadjacent each of the first tooth 2802 and the third tooth 2806. A fourthtooth 2808 may be positioned at a fourth lateral position 2807 acrossthe thickness 2880 of the chain ring. The pattern defined by the firsttooth 2802, the second tooth 2804, the third tooth 2806, and the fourthtooth 2808 may be seen as repeating through each additional set of fourteeth. For example, a fifth tooth 2810 may be positioned at the firstlateral position 2801. A sixth tooth 2812 may be positioned at thesecond lateral position 2803. The seventh tooth 2814 may be positionedat the third lateral position 2805. The eighth tooth 2816 may bepositioned at the fourth lateral position 2807. Finally, a ninth tooth2818 may be positioned at the first lateral position 2801. As may beobserved, the first lateral position 2801, the second lateral position2803, the third lateral position 2805, and the fourth lateral position2807 may differ from one another. The second lateral position 2803 maybe laterally between the first lateral position 2801 and the thirdlateral position 2805. Similarly, the fourth lateral position 2807 maybe laterally between the first lateral position 2801 and the thirdlateral position 2805. The spacing between some of the lateral positionsmay be the same as, or different from, the spacing between the other ofthe lateral positions.

It may be observed that because the pattern is a repeating pattern offour teeth, the pattern may be expressed as starting at any one toothand ending at the fourth tooth therefrom. For example, the pattern maybe expressed as beginning at the first tooth 2802 and ending at thefourth tooth 2808, as beginning at the second tooth 2804 and ending atthe fifth tooth 2810, as beginning at the third tooth 2806 and ending atthe sixth tooth 2812, or starting at the fourth tooth 2808 and ending atthe seventh tooth 2814. In each instance, the series of four teeth maybe described as a repeating pattern.

The first tooth 2802, the fifth tooth 2810, and the ninth tooth 2818 mayeach be positioned at the first lateral position. Three teeth, namely,the second tooth 2804, the third tooth 2806, and the fourth tooth 2808may be circumferentially between the first tooth 2802 and the fifthtooth 2810. Similarly, three teeth, namely, the sixth tooth 2812, theseventh tooth 2814, and the eighth tooth 2816 may be circumferentiallybetween the fifth tooth 2810 and the ninth tooth 2818. As may beobserved, of the three teeth disposed circumferentially between the twoclosest teeth in the first lateral position, one tooth may be in each ofthe second, third, and fourth lateral positions. The tooth in the thirdlateral position may be circumferentially between the tooth in thesecond lateral position and the tooth in the fourth lateral position.

As may further be seen in FIG. 28, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 28 by the dashed line 2830.

In the embodiment of FIG. 28, some of the centerpoints of the tooth endfaces may be seen as being positioned at a peak or valley of thesubstantially undulating pattern 2830. Others of the centerpoints of thetooth end faces may be seen as being positioned away from a peak orvalley of the substantially undulating pattern 2830. For example, afirst centerpoint 2832, a second centerpoint 2838, and a thirdcenterpoint 2842 may each be seen as being positioned at respectivevalleys of the substantially undulating pattern 2830. A fourthcenterpoint 2836 and a fifth centerpoint 2840 may each be seen as beingpositioned at respective peaks of the substantially undulating pattern2830. A sixth centerpoint 2834, a seventh centerpoint 2844, an eighthcenterpoint 2846, and a ninth centerpoint 2848 may each be seen as beingpositioned away from either a peak or valley of the substantiallyundulating pattern 2830.

In the embodiment of FIG. 28, because the substantially undulatingpattern 2830 may be regular around a circumference of the chain ring,there may be a predictable proportion of the teeth that are positionedat each lateral position. In the embodiment of FIG. 28, a quarter of theteeth may be positioned at the first lateral position 2801, a quarter ofthe teeth may be positioned at the third lateral position 2805, and halfthe teeth may be positioned at either the second lateral position 2803or the fourth lateral position 2807.

The embodiment of FIG. 28 may be most suitable in configurations wherethe chain ring has a number of teeth that is divisible by four, i.e.,32, 36, 40, or 44. The regular four-tooth pattern of FIG. 28 is unlikelyto be used on a chain ring that includes a number of teeth not divisibleby four. This is because the precise regularity of the pattern may bebroken when the number of teeth is not divisible by four.

A person having ordinary skill in the art will understand, by comparingthe embodiment of FIG. 28 to the embodiments of FIGS. 11-15 that in thisconfiguration, the second lateral position 2803 and the fourth lateralposition 2807 are substantially equivalent in placement to the secondlateral position shown in the embodiments of FIGS. 11-15. The use of twospaced central positions in the embodiment shown in FIG. 28 is to modifythe lateral forces placed on the chain as shown in FIG. 17.

In the embodiment shown in FIG. 17, the teeth are shown as being similarto that of FIG. 11. FIG. 30 shows how the embodiment of FIG. 28 wouldinteract with the chain to perform a slightly modified function.

The chain 150 may include a first link 3002, which may be an outer link.The chain ring 700 may include a first tooth 3004, which may bepositioned at a first lateral position 3001 across a thickness 3080 ofthe chain ring 700. The first tooth 3004 may be configured to engage thefirst link 3002 at its first lateral side 3006, thereby imparting aforce to the chain 150 in a first lateral direction 3008. The chain 150may include a second link 3010, which may be an inner link. The chainring 700 may include a second tooth 3012, which may be positioned at asecond lateral position 3003 across a thickness 3080 of the chain ring700. The second tooth 3012 may be configured to fit within the secondlink 3010. The second tooth 3012 may be configured to engage the secondlink 3010 at its first lateral side 3011, thereby imparting a force tothe chain 150 in the first lateral direction 3008. The chain 150 mayinclude a third link 3014, which may be an outer link. The chain ring700 may include a third tooth 3016, which may be positioned at a thirdlateral position 3005 across a thickness 3080 of the chain ring 700. Thethird tooth 3016 may be configured to engage the third link 3014 at itssecond lateral side 3018, thereby imparting a force to the chain 150 ina second lateral direction 3020. The chain ring 700 may include a fourthtooth 3022, which may be positioned at a fourth lateral position 3007across a thickness 3080 of the chain ring 700. The fourth tooth 3022 maybe configured to fit within a fourth link 3024, which may be an innerlink. The fourth tooth 3022 may be configured to engage the fourth link3024 at its second lateral side 3026, thereby imparting a force to thechain 150 in the second lateral direction 3020.

In many embodiments with four lateral positions, it may be helpful tomaintain the number of teeth in each lateral position to beapproximately equivalent. Keeping the combined number of teeth in thefirst lateral position 3001 and the second lateral position 3003approximately equal to the combined number of teeth in the third lateralposition 3005 and the fourth lateral position 3007 will cause thelateral force in the first direction 3008 (the first lateral force) andthe lateral force in the second direction 3020 (the second lateralforce) to be approximately equal, which may be desirable in manyembodiments. When either lateral force is applied to the chain 150, thechain 150 is permitted to flex in the direction of the respectivelateral force. In many embodiments, the chain is permitted some lateralgive or play due to its construction. The application of lateral forceby the embodiments disclosed may provide additional security to thechain engagement.

With respect to the embodiment of FIG. 28, it will be apparent to aperson having ordinary skill in the art that teeth in the second lateralposition 2803 and the teeth in the fourth lateral position 2807 combineto perform the function of the teeth in the second lateral position, asdisclosed in other embodiments, e.g. second lateral position 1103 asdescribed in connection with FIG. 11 above, while accommodatingvariations in positions of the abutting faces of the chain due tovariations in link width. While FIG. 28 describes a progression of theteeth going from first to second to third to fourth lateral positions,the person having ordinary skill in the art may instead switch theposition of any tooth in the second lateral position to the fourthlateral position and vice versa. Similarly, a person having ordinaryskill in the art may modify the design of FIG. 28 to incorporate theteachings found in any of the schematics of FIGS. 11-15 and the relateddescription to incorporate the fourth lateral position within thosedesigns.

Turning next to the pattern illustrated in FIG. 29, the patternillustrated may be described as a regular, repeating pattern of twelveteeth using five lateral positions. A first tooth 2902 may be positionedat a first lateral position 2901 across a thickness 2980 of a chainring. A second tooth 2904 may be positioned at a second lateral position2903 across the thickness 2980 of the chain ring. A third tooth 2906 maybe positioned at a third lateral position 2905 across the thickness 2980of the chain ring. The second tooth 2904 may be circumferentiallybetween and circumferentially adjacent each of the first tooth 2902 andthe third tooth 2906. A fourth tooth 2908 may be positioned at thesecond lateral position 2903 across the thickness 2980 of the chainring. A fifth tooth 2910 may be positioned at the first lateral position2901. A sixth tooth 2912 may be positioned at a fourth lateral position2907. The seventh tooth 2914 may be positioned at the third lateralposition 2905. The eighth tooth 2916 may be positioned at a fifthlateral position 2909. A ninth tooth 2918 may be positioned at the firstlateral position 2901. A tenth tooth 2920 may be positioned at the fifthlateral position 2909. An eleventh tooth 2922 may be positioned at thethird lateral position 2905. Finally, a twelfth tooth 2924 may bepositioned at the fourth lateral position 2907. As may be observed, thefirst lateral position 2901, the second lateral position 2903, the thirdlateral position 2905, the fourth lateral position 2907, and the fifthposition 2909 may differ from one another. The second lateral position2903 may be laterally between the first lateral position 2901 and thethird lateral position 2905. Similarly, the fourth lateral position 2907and the may be laterally between the first lateral position 2901 and thethird lateral position 2905. The fifth lateral position 2909 may belaterally between the first lateral position 2901 and the third lateralposition 2905.

The first tooth 2902, the fifth tooth 2910, and the ninth tooth 2918 mayeach be positioned at the first lateral position. Three teeth, namely,the second tooth 2904, the third tooth 2906, and the fourth tooth 2908may be circumferentially between the first tooth 2902 and the fifthtooth 2910. Similarly, three teeth, namely, the sixth tooth 2912, theseventh tooth 2914, and the eighth tooth 2916 may be circumferentiallybetween the fifth tooth 2910 and the ninth tooth 2918. As may beobserved, of the three teeth disposed circumferentially between the twoclosest teeth in the first lateral position, each tooth may be in any ofthe second, third, fourth, and fifth lateral positions. The tooth in thethird lateral position may be circumferentially between two teeth in twoof the other lateral positions.

As may further be seen in FIG. 29, each end face can be seen as having acenterpoint. A substantially undulating pattern can be seen by drawing aline or curve between centerpoints of adjacent teeth. This pattern isdrawn schematically in FIG. 29 by the dashed line 2930.

The embodiment of FIG. 29 may be most suitable in configurations wherethe chain ring has a number of teeth that is divisible by four, i.e.,32, 36, 40, or 44. The regular four-tooth patterns of FIG. 29 areunlikely to be used on a chain ring that includes a number of teeth notdivisible by four. This is because the precise regularity of the patternmay be broken when the number of teeth is not divisible by four.However, additional teeth may be added in the second, fourth, or fifthlateral positions adjacent any other tooth in the second, fourth, orfifth lateral positions as may be desired.

A person having ordinary skill in the art will understand, by comparingthe embodiment of FIG. 29 to the embodiments of FIGS. 11-15 that in theFIG. 29 configuration, the second lateral position 2903, the fourthlateral position 2907, and the fifth lateral position 2909 aresubstantially equivalent in placement to the second lateral positionshown in the embodiments of FIGS. 11-15. The use of three spaced centralpositions in the embodiment shown in FIG. 29 is to modify the lateralforces placed on the chain as shown in FIG. 17.

In the embodiment shown in FIG. 17, the teeth are shown as being similarto that of FIG. 11. FIG. 31 shows how the embodiment of FIG. 29 wouldinteract with the chain to perform a slightly modified function.

The chain 150 may include a first link 3102, which may be an outer link.The chain ring 700 may include a first tooth 3104, which may bepositioned at a first lateral position 3101 across a thickness 3180 ofthe chain ring 700. The first tooth 3104 may be configured to engage thefirst link 3102 at its first lateral side 3106, thereby imparting aforce to the chain 150 in a first lateral direction 3108. The chain 150may include a second link 3110, which may be an inner link. The chainring 700 may include a second tooth 3112, which may be positioned at asecond lateral position 3103 across a thickness 3080 of the chain ring700. The second tooth 3112 may be configured to fit within the secondlink 3110. The second tooth 3112 may be configured to engage the secondlink 3110 at its second lateral side 3111, thereby imparting a force tothe chain 150 in the second lateral direction 3120. The chain 150 mayinclude a third link 3114, which may be an outer link. The chain ring700 may include a third tooth 3116, which may be positioned at a thirdlateral position 3105 across the thickness 3180 of the chain ring 700.The third tooth 3116 may be configured to engage the third link 3114 atits second lateral side 3118, thereby imparting a force to the chain 150in a second lateral direction 3120. The chain ring 700 may include afourth tooth 3124, which may be positioned at a second lateral position3103 across the thickness 3180 of the chain ring 700. The fourth tooth3124 may be configured to fit within a fourth link 3122, which may be aninner link. The fourth tooth 3124 may be configured to engage the fourthlink 3122 at its second lateral side 3126, thereby imparting a force tothe chain 150 in the second lateral direction 3120. The chain 150 mayinclude a fifth link 3128, which may be an outer link. The chain ring700 may include a fifth tooth 3130, which may be positioned at a firstlateral position 3101 across the thickness 3180 of the chain ring 700.The fifth tooth 3130 may be configured to engage the fifth link 3128 atits first lateral side 3132, thereby imparting a force to the chain 150in the first lateral direction 3108. The chain 150 may include a sixthlink 3134, which may be an inner link. The chain ring 700 may include asixth tooth 3133, which may be positioned at a fourth lateral position3107 across the thickness 3180 of the chain ring 700. The sixth tooth3133 may be configured to fit within the sixth link 3134 and impartsubstantially no lateral force to the sixth link 3134. The chain 150 mayinclude a seventh link 3136, which may be an outer link. The chain ring700 may include a seventh tooth 3138, which may be positioned at a thirdlateral position 3105 across the thickness 3180 of the chain ring 700.The seventh tooth 3138 may be configured to engage the seventh link 3136at its second lateral side 3140, thereby imparting a force to the chain150 in the second lateral direction 3120. The chain 150 may include aneighth link 3142. The chain ring 700 may include an eighth tooth 3144,which may be positioned at a fifth lateral position 3109 across thethickness 3180 of the chain ring 700. The eighth tooth 3144 may beconfigured to fit within the eighth link 3142, which may be an innerlink. The eighth tooth 3144 may be configured to engage the eighth link3142 at its first lateral side 3146, thereby imparting a force to thechain 150 in the first lateral direction 3108. The chain 150 may includea ninth link 3148, which may be an outer link. The chain ring 700 mayinclude a ninth tooth 3150, which may be positioned at a first lateralposition 3101 across the thickness 3180 of the chain ring 700. The ninthtooth 3150 may be configured to engage the ninth link 3148 at its firstlateral side 3152, thereby imparting a force to the chain 150 in thefirst lateral direction 3108. The chain 150 may include a tenth link3154, which may be an inner link. The chain ring 700 may include a tenthtooth 3156, which may be positioned at a fifth lateral position 3109across a thickness 3080 of the chain ring 700. The tenth tooth 3156 maybe configured to engage the tenth link 3154 at its first lateral side3158, thereby imparting a force to the chain 150 in the first lateraldirection 3108. The chain 150 may include an eleventh link 3160, whichmay be an outer link. The chain ring 700 may include an eleventh tooth3162, which may be positioned at a third lateral position 3105 acrossthe thickness 3180 of the chain ring 700. The eleventh tooth 3162 may beconfigured to engage the eleventh link 3160 at its second lateral side3164, thereby imparting a force to the chain 150 in a second lateraldirection 3120. The chain 150 may include a twelfth link 3166. The chainring 700 may include a twelfth tooth 3168, which may be positioned at afourth lateral position 3107 across a thickness 3180 of the chain ring700. The twelfth tooth 3168 may be configured to fit within the twelfthlink 3166, which may be an inner link. The twelfth tooth 3168 may beconfigured to fit within the twelfth link 3166 and impart substantiallyno lateral force to the twelfth link 3166.

In many embodiments with four lateral positions, it may be helpful tomaintain appropriate proportions of teeth in each lateral position.Keeping the combined number of teeth in the first lateral position 3101and the fifth lateral position 3109 approximately equal to the combinednumber of teeth in the second lateral position 3103 and the thirdlateral position 3105 will cause the lateral force in the firstdirection 3108 (the first lateral force) and the lateral force in thesecond direction 3120 (the second lateral force) to be approximatelyequal, which may be desirable in many embodiments. When either lateralforce is applied to the chain 150, the chain 150 is permitted to flex inthe direction of the respective lateral force. In many embodiments, thechain is permitted some lateral give or play due to its construction.The application of lateral force by the embodiments disclosed mayprovide additional security to the chain engagement.

With respect to the embodiment of FIG. 29, it will be apparent to aperson having ordinary skill in the art that teeth in the second lateralposition 2903, the teeth in the fourth lateral position 2907, and theteeth in the fifth lateral position 2909 combine to perform the functionof the teeth in the second lateral position, as disclosed in otherembodiments, e.g. second lateral position 1103 as described inconnection with FIG. 11 above. While FIG. 29 describes a progression ofthe teeth in various lateral positions, the person having ordinary skillin the art may instead switch the position of any tooth among thesecond, fourth, and fifth lateral positions. Similarly, a person havingordinary skill in the art may modify the design of FIG. 29 toincorporate the teachings in any of the schematics of FIGS. 11-15 andthe related description to incorporate the fourth and fifth lateralpositions within those designs.

Further, in any of the illustrated embodiments, the end face of anytooth may be the same as or different from the end face of any othertooth in shape and size. A person having ordinary skill in the art willunderstand that the schematic views of the various embodiments aresimplified to show an overall structure, not a detailed structure withteeth of a particular size and shape. Teeth having various sizes andshapes may be used in any of the embodiments within the size and shaperestrictions of a typical chain 150. In some embodiments, however, theuse of a tooth with an increased size may be useful.

One such alternative embodiment is shown in FIG. 32. FIG. 32 is aschematic, rather than detailed, view of a design that shows a tooththat spans multiple lateral positions. Such an embodiment mayadvantageously be used in the context of an embodiment like thatillustrated and described in connection with FIG. 12. The embodiment ofFIG. 32 may be used if, for example, a chain ring is used that has aneven number of teeth that is not divisible by four, i.e., 34, 38, 42, or46. In such a configuration, the addition of one tooth in the secondlateral position and one tooth that spans multiple lateral positions maybe desirable. Of course, a person having ordinary skill in the art mayelect to add such a pattern of teeth in any position along the chainring.

A first tooth 3202 may be positioned at a first lateral position 3201across a thickness 3280 of a chain ring. A second tooth 3204 may bepositioned at a second lateral position 3203 across the thickness 3280of the chain ring. A third tooth 3206 may be positioned at a thirdlateral position 3205 across the thickness 3280 of the chain ring. Thesecond tooth 3204 may be circumferentially between and circumferentiallyadjacent each of the first tooth 3202 and the third tooth 3206. A fourthtooth 3208 may be positioned at the second lateral position 3203 acrossthe thickness 3280 of the chain ring. After the fourth tooth 3208, thefour-tooth pattern may be seen as being broken. Instead, a fifth tooth3210 that spans multiple lateral positions may be included.

The fifth tooth 3210 may, as shown in FIG. 32, span all three lateralpositions 3201, 3203, 3205. In some embodiments, it may be desirable forthe fifth tooth 3210 to make such a span to fill substantially an entirewidth of an outer link of a chain in which it is configured tointermesh. In other embodiments, it may be desirable for such a tooth toencompass only two lateral positions, whether spanning the first 3201and second 3203 lateral positions or the second 3203 and third 3205lateral positions. As noted in connection with earlier embodiments,where there may be more than three lateral positions, a span of adifferent subset of lateral positions may be made without undueexperimentation. The use of such a tooth may be useful in some contexts.Such a tooth may be configured to create a lateral force on a link ofthe chain in at least one direction, as may be deemed desirable by adesigner. After the inclusion of the fifth tooth 3210, a sixth tooth3212 may be positioned at the second lateral position circumferentiallyadjacent the fifth tooth 3210. The remaining pattern and features shownin FIG. 32 will be understood to be substantially identical to thepattern and features shown in FIG. 12.

This detailed description in connection with the drawings is intendedprincipally as a description of the presently preferred embodiments ofthe invention, and is not intended to represent the only form in whichthe present invention may be constructed or utilized. The descriptionsets forth the designs, functions, means, and methods of implementingthe invention in connection with the illustrated embodiments. It is tobe understood, however, that the same or equivalent functions andfeatures may be accomplished by different embodiments that are alsointended to be encompassed within the spirit and scope of the inventionand that various modifications may be adopted without departing from theinvention or scope of any claims.

The invention claimed is:
 1. A drivetrain for a vehicle, comprising: achain having a centerline; and a chain ring comprising a plurality ofteeth joined to one another and serially arranged; wherein each of theplurality of teeth is positioned laterally across a thickness of thechain ring; wherein the position of each of the plurality of teeth maybe averaged to calculate an average tooth position laterally across thethickness; wherein the average tooth position of the plurality of teethis offset from the chain centerline when in operative position; andwherein each of the plurality of teeth has a thickness and the thicknessof each of the plurality of teeth at its respective thickest point issubstantially identical.
 2. The drivetrain according to claim 1, whereinabout half of the plurality of teeth are positioned in one lateralposition across the thickness of the chain ring.
 3. The drivetrainaccording to claim 2, wherein at least the remainder of the plurality ofteeth are offset from the centerline of the chain.
 4. The drivetrainaccording to claim 2, wherein at least a portion of the remainder of theplurality of teeth are offset from the centerline of the chain in asingle direction.
 5. The drivetrain according to claim 1, wherein atleast about half of the plurality of teeth are offset from thecenterline of the chain.
 6. The drivetrain according to claim 5, whereineach of the plurality of teeth is offset from the centerline of thechain.
 7. A drive system for a vehicle, comprising: a drive chain havinga plurality of inner links and a plurality of outer links, each linkcomprising an inner plate and an opposite outer plate, each inner platehaving a first inner surface facing the outer plate and each outer platehaving a second inner surface facing the inner plate; and a chain ringhaving a plurality of teeth joined to one another and serially arranged;wherein each of the plurality of teeth is configured to interfit with arespective one of the plurality of links of the drive chain; whereineach of the plurality of teeth has a thickness, the thickness of each ofthe plurality of teeth at its respective thickest point beingsubstantially identical; wherein the plurality of teeth comprises afirst set of teeth and a second set of teeth; wherein each of theplurality of teeth has a first outer surface and a first inner surface;wherein each of the inner surface and the outer surface of each of thefirst set of teeth is permitted to contact a corresponding inner surfaceof one of the inner or outer plate of a respective chain link with whichit interfits in operative position when the chain interfits withoutshifting between rings; and wherein at least one portion of one of thefirst outer surface and the first inner surface of each of the secondset of teeth remains spaced from only one of the first and second innersurfaces of the respective link with which each of the second set ofteeth interfits in operative position when the chain interfits withoutshifting between rings.
 8. The drive system for a vehicle according toclaim 7, wherein the at least one portion of the second set of teeth isspaced from the outer plate.
 9. The drive system for a vehicle accordingto claim 7, wherein the at least one portion of each of the second setof teeth is spaced from the inner plate.
 10. The drive system for avehicle according to claim 7, wherein each of the second set of teeth isconfigured to contact only one of the inner plate and the outer plate.11. The drive system for a vehicle according to claim 10, wherein eachof the second set of teeth is configured to contact the inner plate. 12.The drive system for a vehicle according to claim 10, wherein each ofthe second set of teeth is configured to contact the outer plate.
 13. Adrive system for a vehicle, comprising: a drive chain having a pluralityof inner links, a plurality of outer links, and a centerline; whereineach link comprises a first plate and a second plate; and a chain ringhaving a plurality of teeth joined to one another and serially arranged;wherein each of the plurality of teeth has a thickness, the thickness ofeach of the plurality of teeth at its respective thickest point beingsubstantially identical; wherein the plurality of teeth comprises afirst set of teeth and a second set of teeth; wherein each tooth of thesecond set of teeth is configured to fit within one of the outer linksof the drive chain in operative position; wherein an average toothposition of the second set of teeth is offset from the chain centerlinewhen in operative position; wherein each tooth in the second set ofteeth has a cross section taken on a plane extending laterally acrossthe tooth; wherein the cross section is substantially hat shaped, thecross section having a circumferentially longer portion and acircumferentially shorter portion.
 14. The drive system for a vehicleaccording to claim 13, wherein the shorter portion of each of the secondset of teeth is configured to face a first direction.
 15. The drivesystem for a vehicle according to claim 14, wherein the shorter portionof each of the second set of teeth is configured to face the first plateof each of the outer links of the drive chain.
 16. The drive system fora vehicle according to claim 13, wherein each tooth of the first set ofteeth is configured to fit within one of the inner links of the drivechain in operative position.
 17. The drive system for a vehicleaccording to claim 13, wherein each tooth in the first set of teeth hasa hat shaped cross section having a longer portion and a shorterportion.
 18. The drive system for a vehicle according to claim 17,wherein the shorter portion of each of the first set of teeth isconfigured to face a second direction.
 19. The drive system for avehicle according to claim 18, wherein the shorter portion of each ofthe first set of teeth is configured to face the second plate of each ofthe outer links of the drive chain.